#ifndef _SYS_CSPRNG_H_
#define _SYS_CSPRNG_H_

#include <crypto/chacha20/_chacha.h>
#include <crypto/sha2/sha2.h>

#include <sys/callout.h>
#include <sys/spinlock.h>
#include <sys/time.h>
#include <sys/ibaa.h>

/* Flags for various calls */
#define CSPRNG_TRYLOCK          0x0001
#define CSPRNG_UNLIMITED        0x0002  /* unlimited (/dev/urandom) read */

struct csprng_pool {
        uint64_t        bytes;
        SHA256_CTX      hash_ctx;
};

CTASSERT(SHA256_DIGEST_LENGTH == 32);

struct csprng_state {
        uint8_t         key[SHA256_DIGEST_LENGTH];

        uint64_t        reseed_cnt;     /* Times we have reseeded */

        struct chacha_ctx cipher_ctx;   /* (Stream) cipher context */

        /* Pools and the per-source round robin pool index */
        struct csprng_pool pool[32];
        uint8_t         src_pool_idx[256];

        struct spinlock spin;
        struct callout  reseed_callout;
        uint32_t        failed_reseeds;
        int             callout_based_reseed;
        uint8_t         inject_counter[256];
        long            nrandevents;
        long            nrandseed;
        struct timeval  last_reseed;
        struct ibaa_state ibaa;
        struct l15_state l15;
} __cachealign;

int csprng_init(struct csprng_state *state);
int csprng_get_random(struct csprng_state *state, uint8_t *out, int bytes,
    int flags);
int csprng_add_entropy(struct csprng_state *state, int src_id,
    const uint8_t *entropy, size_t bytes, int flags);

#endif